BR102021024572A2 - NON-PNEUMATIC TIRE - Google Patents

Abstract

NON-PNEUMATIC TIRE A non-pneumatic tire and wheel assembly, including a wheel having a first and second bead rings, a non-pneumatic tire having a shear and tread band forming a tread, and a first and second sidewall region ; wherein the first and second sidewall regions each extend from the tread and terminate in a respective first and second bead areas, wherein the first and second bead areas are mounted on the first and the second bead. second bead ring, respectively; wherein each bead area is located axially outward from the crown region of the non-pneumatic tire when mounted on the wheel, and wherein the first and second sidewalls each have an upper sidewall region that is decoupled of the outer side edges of the tread.

Description

NON-PNEUMATIC TIRE FIELD OF THE INVENTION

[001] The present invention relates generally to vehicle tires and more particularly to a non-pneumatic tire.

FUNDAMENTALS OF THE INVENTION

[002] The pneumatic tire has been the solution of choice for vehicle mobility for over a century. The pneumatic tire is a tensioned structure. The pneumatic tire has at least four characteristics that make the pneumatic tire so dominant today. Pneumatic tires are efficient in carrying loads because the entire tire structure is involved in carrying the load. Pneumatic tires are also desirable as they have low contact pressure, resulting in less road wear due to vehicle load distribution. Pneumatic tires also have low stiffness, which ensures a comfortable ride in the vehicle. The main disadvantage of a pneumatic tire is that it requires compressed fluid. A conventional pneumatic tire becomes useless after a complete loss of inflation pressure.

[003] A tire designed to operate without inflation pressure can eliminate many of the problems and compromises associated with a tire. Neither pressure maintenance nor pressure monitoring is necessary. Structurally supported tires, such as solid tires or other elastomeric structures, have so far not provided the performance levels required of a conventional tire. A structurally supported tire solution that offers similar performance to a pneumatic tire would be a desirable improvement.

[004] Non-pneumatic tires are typically defined by their load-carrying efficiency. “Bottom loaders” are essentially rigid structures that support most of the load on the part of the structure below the hub. “Top loaders” are designed so that the entire structure is involved in carrying the load. Top loaders therefore have a higher load carrying efficiency than bottom loaders, allowing for a design that has less mass.

[005] Thus, an improved non-pneumatic tire that has all the characteristics of pneumatic tires without the disadvantage of needing air inflation is desired.

SUMMARY OF THE INVENTION

[006] The invention provides, in a first aspect, a non-pneumatic wheel and tire assembly including a wheel having a first and a second bead ring, a non-pneumatic tire having a shear and tread band forming a tread band. , and a first and a second sidewall region; wherein the first and second sidewall regions each extend from the tread and terminate in a respective first and second bead area, wherein the first and second bead areas are mounted on the first and second bead areas. on the second bead ring, respectively; wherein each bead area is located axially away from the crown region of the non-pneumatic tire when mounted on the wheel, and wherein the first and second sidewalls each have an upper sidewall region that is uncoupled from the outer side edges of the tread.

BRIEF DESCRIPTION OF THE DRAWINGS

[007] The present invention will be better understood through reference to the following description and the accompanying drawings, in which:
Figure 1 is a cross-sectional view of the non-pneumatic tire of Figure 1 mounted on a wheel rim;
Figure 2 is a cross-sectional view of a second embodiment of a non-pneumatic tire;
Figure 3 is a cross-sectional view of the non-pneumatic tire of Figure 2, shown mounted on a wheel rim; and
Figure 4 is a close-up cross-sectional view of one half of a pneumatic tire of the present invention.

DEFINITIONS

[008] “Screen Ratio” means the ratio between the height of a section of a tire and the width of its section.

[009] “Axial” or “axial direction” means the lines or directions that are parallel to the tire's axis of rotation.

[010] "Bead" or "bead core" means, in general, that part of the tire that comprises an annular traction element, the radially inner beads are associated with holding the tire to the rim being wrapped by mesh cords and molded. , with or without other reinforcing elements such as flippers, chippers, wedges or padding, protectors (toe guards) and chafers.

[011] "Belt structure" or "reinforcement belts" means at least two layers or annular fabrics of parallel strands, woven or non-woven, underlying the tread, not attached to the bead and with left and right strand angles on the range of 17º to 27º in relation to the equatorial plane of the tire.

[012] “Guards” or “tire protectors” means the same as belt or belt structure or reinforcement belts.

[013] “Carcass” means a laminate of tire ply material and other tire components cut to length suitable for splicing, or already spliced, into a cylindrical or toroid shape. Other components can be added to the carcass before it is vulcanized to create the molded tire.

[014] “Circumferent” means lines or directions extending along the perimeter of the annular tread surface perpendicular to the axial direction; can also refer to the direction of adjacent sets of circular curves whose radii define the axial curvature of the tread, as viewed in cross-section.

[015] “Cord” means one of the reinforcing filaments, including fibers, which are used to reinforce fabrics.

[016] “Inextensible” means a cord having a relative elongation at break of less than 0.2% to 10% of the breaking load when measured from a cord extracted from a cured tire.

[017] "Equatorial plane" means a plane perpendicular to the tire's axis of rotation that passes through the tire's centerline.

[018] "Meridian plane" means a plane parallel to the tire's axis of rotation and extending radially outward from said axis.

[019] "Mesh" means a bead reinforced layer of elastomer-coated cords, deployed radially or otherwise parallel.

[020] “Radial” and “radially” mean directions radially towards or away from the tire's axis of rotation.

[021] "Radial ply structure" means one or more carcass plies or that at least one ply has reinforcing cords oriented at an angle between 65º and 90º in relation to the equatorial plane of the tyre.

[022] "Radial ply tire" means a belted or restricted circumference pneumatic tire, in which ply cords extending from bead to bead are oriented at cord angles between 65° and 90° in relation to the equatorial plane of the tyre.

[023] “Sidewall” means a portion of a tire between the tread and the bead.

[024] “Laminated Structure” means an unvulcanized structure made of one or more layers of tire or elastomer components, such as the inner lining, sidewalls and optional fabric layer.

DETAILED DESCRIPTION OF THE INVENTION

[025] As shown in Figures 1-4, a non-pneumatic tire 100 of the present invention includes a tread radially against the external ground 200, which may be a conventional tread, as desired, and may include elements such as ribs. , blocks, bumps, grooves and sipes as desired to improve tire performance in various conditions.

[026] In a first embodiment of a shear band 300, the shear band is composed of at least two inextensible reinforcement layers 310, 320 arranged in parallel and separated by an elastomer shear matrix 315. Each reinforcement layer 310, 320 may be formed of parallel reinforcement cords embedded in a thin elastomeric coating. The reinforcing cords are preferably inextensible and may be made of steel, aramid, nylon, polyester or other inextensible structure. In the first reinforced elastomer layer 310, the reinforcing cords are oriented at an angle in the range of 0 to about +/- 50 degrees to the equatorial plane of the tire and, more preferably, in the range of 0 to +/- 10 degrees. In the second reinforced elastomer layer 320, the reinforcement cords are oriented at an angle in the range of 0 to about +/- 50 degrees relative to the equatorial plane of the tire, more preferably from 0 to +/- 10 degrees. Preferably, the angle of the reinforcing strands of the first layer is in the opposite direction to the angle of the reinforcing strands of the second layer. As shown, the shear band 300 may optionally further include as many additional reinforcement layers 330-360 as desired to achieve the desired stiffness. It is further preferred that the radially outermost reinforcement layers 350, 360 have outer side ends 351, 361 having a reduced axial width compared to the radially inner reinforcement layers 310-340.

[027] The shear matrix layer 315 is located between the first and second reinforcement layers 310, 320 and is formed by an elastomer material with a shear modulus Gm in the range of 0.5 to 10 MPa and, more preferably in the range of 4 to 8 MPa. The thickness of the rubber layer 315 may have a radial thickness in the range of between about 0.10 inches and 0.2 inches, more preferably approximately 0.15 inches. If additional reinforcement layers 330-360 are used, the reinforcement layers may also optionally be separated by the shear layer 315. The belt pack together with the shear layer forms a shear band. The shear band together with the tread forms an outer annular tread.

[028] As shown in Figure 1, the non-pneumatic tire 100 of the present invention further includes two axially spaced apart sidewall portions 400 that extend inwardly from the tread to a wheel 50. The central portion of the tread is in the range of 80-90% of the total axial width of the tread, while the side edges are the remaining balance. The outer ends in the axial direction of the tread are uncoupled from the housing.

[029] The radially innermost end 410 of each sidewall preferably includes an annular bead 420 which is secured to the wheel. The non-pneumatic tire 100 further includes a first layer of ply 500 that extends from the first bead 420 to the second bead 422. Preferably, the ply 500 comprises a reinforced rubber or fabric layer formed of parallel reinforcing cords that are nylon, polyester , aramid or formed by a blended cord of nylon, polyester or aramid. Preferably, the ribs are oriented in the radial direction. The web layer extends radially inwardly from the tread and is then wrapped around the first bead 420 and has a first end 510 which preferably terminates under the shear band 300 forming an envelope web. A second end 520 of the web also extends inwardly from the tread, is wrapped around the opposite bead 420, and then preferably ends under the shear band forming an envelope layer. Thus, each sidewall preferably has two effective layers of fabric. Alternatively, the first and second ends 510,520 may encircle the bead and terminate radially outward from a tip 432 of a wedge 430.

[030] Each wedge 430 is preferably triangular in shape and has a radial height measured from the first end 431 to the tip 432. The radial height of the outer tip 432 is preferably in the range of ¼ to 3/4 of the radial height of the sidewall, and more preferably in the range of 1/3 to 2/3 of the radial height of the sidewall. Each region of the lower sidewall, which is defined as the lower half of the sidewall, is preferably stiffer with respect to the stiffness of the upper half of the sidewall. The bottom sidewall can be increased rigidity by a rigid wedge or additional rigid material in the bottom sidewall region, such as a chafer or rim flange protector. Additional rigid material may be located on the axially outer portion of the lower sidewall, such as a rim flange protector or chafer, or an axially inner portion, such as a secondary wedge.

[031] Stiffness, which is the flexural strength, can be characterized by the dynamic modulus G', which is sometimes referred to as the “shear storage module” or “dynamic module”, and reference can be made to Science and Technology of Rubber, second edition, 1994, Academic Press, San Diego, California, edited by James E. Mark et al, pages 249-254. The shear storage modulus (G') values are indicative of the stiffness of the rubber compound that may be related to tire performance. The tangent delta value at 100 °C is considered indicative of hysteresis or heat loss.

[032] In a first embodiment, the first wedge 430 comprises a rigid rubber composition with a shear storage modulus G' measured at 1% strain and 100°C, according to ASTM D5289, ranging from 14 to 43 MPa. In a more preferred embodiment, the first wedge 430 comprises a rubber composition with a shear storage modulus G' measured at 1% strain and 100°C, in accordance with ASTM D5289, ranging from 23 to 43 MPa.

[033] The hardened lower side wall ensures that the screen is in tension after being mounted on the wheel and also during use. When the ply and sidewall of the tire are in the relaxed state, the ply line is curved so that the beads are located inwardly in the axial direction of the shoulders of the tire. When the beads are loaded into the rim, the bend is straightened and the bead or lower sidewall of the tire is moved out in the axial direction, while preferably remaining within the axial width of the tire's shoulders, so that the fabric acts as a spring. .

[034] Figure 2 illustrates a second embodiment 2000 of a non-pneumatic tire of the present invention mounted on the wheel. By design, the length of the molded fabric is greater than the minimum distance between the molded strands and the shear band. In this 2000 design, this is accomplished by creating an increased radius R2 at the top 2450 of a second wedge 2400. In this design, the radius under the tread R1 is much larger than the radius R2 at the top of the second wedge. This design provides a mechanism for the strands to remain in tension while the shear band deforms in and out of the passage. The second wedge 2400 acts as a spring and provides the tension rigidity of the side walls. The shear band is loaded so that it is compressed in the circumferential direction. This mesh geometry combination will evenly distribute the load from the shear band across its entire width, across a size dependent range of rim widths and vertical deflections. In a second embodiment, the first and/or second wedge each comprises a rigid rubber composition with a shear storage modulus G' measured at 1% strain and 100°C, in accordance with ASTM D5289, ranging from 14 to 43 MPa, and more preferably ranging from 23 to 43 MPa.

[035] Figure 3 illustrates the tire mounted on the wheel with the fabric tensioned on the side walls. The beads are seated in the 900 L-shaped recesses as shown. In order to pre-tension the fabric, the bead supports of the rim surface 1000 are moved outwards in the axial direction until the desired pre-tension is achieved. The tension of the fabric cords ensures that the tire is 100% from a top loader. Compared to a run flat tire, where the stiffened sidewall members carry the load because the run flat tire functions as a bottom loader.

[036] As shown in Figure 3, the layers of the shear band remain horizontal after the tire sidewalls are pre-tensioned, because the layer line geometry is designed to distribute the compressive load of the shear band evenly across the entire tire. shear band width. The deformed shape of the screen line is between the molded shape and a fully fitted shape. A fully engaged shape is defined with R1 and R3 being minimized to 0 (approaching linear discontinuity), and with R2 approaching infinity (Linear). Figure 2. The maximum axial position of the rim will remain at or below this fully engaged layer geometry.

[037] The stiffness of each sidewall and, more preferably, the lower half of the sidewall contributes to the top loading of the non-pneumatic tire. The lower half of each sidewall is preferably rigid and may be stiffened by a rigid wedge and/or a mass of rigid material located on the outer portion in the axial direction, such as a chafer or rim flange protector. The sidewalls of the tire were pre-tensioned by expanding the wheel rim in the axial direction. In a third embodiment, a chafer or rim flange protector located outside the wedge, in the axial direction, comprises a rigid rubber composition having a shear storage modulus G' measured at 1% strain and 100°C, in accordance with with ASTM D5289, ranging from 14 to 43 MPa, and more preferably from 23 to 43 MPa.

[038] Figure 4 illustrates an alternative embodiment that shows an alternative screen line that has less curvature. The alternate embodiment may also have 3-dimensional alternating molded holes to reduce weight. This would give the appearance of lightning.

[039] Variations on the present invention are possible in light of the description provided herein. While certain embodiments and representative details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in the art that various changes and modifications can be made thereto without departing from the scope of the subject invention. It is therefore to be understood that changes may be made to the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims.

Claims (10)

Non-pneumatic tire and wheel assembly, CHARACTERIZED in that it comprises: a wheel having a first and a second bead ring support, a non-pneumatic tire with a shear and tread band forming a tread band and a first and a second sidewall region; wherein the first and second sidewall regions each extend from the tread and terminate in a first and second respective bead area, wherein a carcass ply extends under a crown portion of the tire non-pneumatic and into the first and second sidewall regions and has a first end attached to a first bead area and a second end attached to a second bead area, wherein the first and second bead areas are mounted each on the first and second bead ring support; and wherein the carcass fabric is tensioned when each bead area is mounted on the respective bead support of the wheel. A non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED in that the first and second sidewalls each have an upper sidewall region that is not connected to an outer side edge of the tread . Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that each bead is tensioned outwards, but located inwards, in the axial direction, of a respective shoulder of the non-pneumatic tire when mounted on the wheel. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that when the non-pneumatic tire is not mounted on the wheel and is in an unloaded condition, the carcass fabric has a first radius R1 under a region of the crown of the tread, and a second radius R2 on the upper sidewall at the decoupled location, and where R1 is greater than R2. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that the shear band is loaded in compression when the non-pneumatic tire is mounted on the wheel. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that the shear band is compressed in the circumference when the non-pneumatic tire is mounted on the wheel. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that the axial distance between the first and second bead ring is adjustable in the axial direction. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that each side wall has at least two layers of reinforcing fabric. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that the first end and the second end of the carcass fabric are located in the crown portion of the tire. Non-pneumatic tire and rim assembly according to claim 1, CHARACTERIZED by the fact that the side walls are angled at an angle α in relation to a horizontal surface of the rim.

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